Abstract:Objective
Head direction cell and place cell spatially tuned firing is often anchored to salient visual landmarks on the periphery of a recording environment. What is less well understood is whether structural features of an environment, such as orientation of a maze sub‐compartment or a polarizing barrier, can likewise control spatial firing.
Method
We recorded from 54 head direction cells in the medial entorhinal cortex and subicular region of male Lister Hooded rats while they explored an apparatus with fou… Show more
“…This observation was then extended to two-compartment environments in which rats could walk under their own volition from one compartment to another [ 16 ] ( figure 4 b ), where it was found that firing directions would be aligned provided the second environment was novel when the rat did so (see also [ 17 ]). Firing directions of classic head direction cells also remain aligned across two connected compartments even if the visual scenes are rotated with respect to each other [ 18 , 19 ] (but see below for non-classic directional cells). Thus, it seems that self-motion cues can be used to coordinate the signals across the two spaces: something that may be adaptive for navigation.…”
Section: Spatial Symmetriesmentioning
confidence: 99%
“…This dissociation between translation and rotation might be explained by the dissociable routes in to the system of directional information (via the head direction system) versus linear motion information (the source of which is still not identified). These two information sources, which we assume to be responsible for the rotational and translational symmetry respectively, can be placed in conflict if the local environment is rotated with respect to the global, room environment: in this situation grid cells rotate their grids somewhat [ 46 ], and it seems head direction cells may also do so as well, although very subtly [ 18 ], indicating that both global and local cues can contribute to directional calculations. Figure 5 Symmetry-breaking in grid cells.…”
The neural coding of space centres on three foundational cell types: place cells, head direction cells and grid cells. One notable characteristic of these neurons is the symmetry properties of their spatial firing patterns. In symmetric environments, firing patterns are often also symmetric: for example, place cells show translational symmetry in aligned sub-compartments of a multi-compartment environment. A single head direction cell has a mirror-symmetric firing pattern, while a sub-class of head direction cells can show multi-fold rotational symmetries in multi-compartment environments, matching the symmetry of the recently experienced environment. The entorhinal grid cells are notable for the symmetry of their firing patterns in both rotational and translational domains. However, these symmetries are broken in a variety of situations. These symmetry-making and -breaking observations shed light on the underlying computations that generate these firing patterns, and also invite speculation as to whether they may have a functional role. This article outlines these findings and speculates on the consequences of the resultant firing symmetries and asymmetries for spatial coding and cognition.
This article is part of a discussion meeting issue ‘New approaches to 3D vision’.
“…This observation was then extended to two-compartment environments in which rats could walk under their own volition from one compartment to another [ 16 ] ( figure 4 b ), where it was found that firing directions would be aligned provided the second environment was novel when the rat did so (see also [ 17 ]). Firing directions of classic head direction cells also remain aligned across two connected compartments even if the visual scenes are rotated with respect to each other [ 18 , 19 ] (but see below for non-classic directional cells). Thus, it seems that self-motion cues can be used to coordinate the signals across the two spaces: something that may be adaptive for navigation.…”
Section: Spatial Symmetriesmentioning
confidence: 99%
“…This dissociation between translation and rotation might be explained by the dissociable routes in to the system of directional information (via the head direction system) versus linear motion information (the source of which is still not identified). These two information sources, which we assume to be responsible for the rotational and translational symmetry respectively, can be placed in conflict if the local environment is rotated with respect to the global, room environment: in this situation grid cells rotate their grids somewhat [ 46 ], and it seems head direction cells may also do so as well, although very subtly [ 18 ], indicating that both global and local cues can contribute to directional calculations. Figure 5 Symmetry-breaking in grid cells.…”
The neural coding of space centres on three foundational cell types: place cells, head direction cells and grid cells. One notable characteristic of these neurons is the symmetry properties of their spatial firing patterns. In symmetric environments, firing patterns are often also symmetric: for example, place cells show translational symmetry in aligned sub-compartments of a multi-compartment environment. A single head direction cell has a mirror-symmetric firing pattern, while a sub-class of head direction cells can show multi-fold rotational symmetries in multi-compartment environments, matching the symmetry of the recently experienced environment. The entorhinal grid cells are notable for the symmetry of their firing patterns in both rotational and translational domains. However, these symmetries are broken in a variety of situations. These symmetry-making and -breaking observations shed light on the underlying computations that generate these firing patterns, and also invite speculation as to whether they may have a functional role. This article outlines these findings and speculates on the consequences of the resultant firing symmetries and asymmetries for spatial coding and cognition.
This article is part of a discussion meeting issue ‘New approaches to 3D vision’.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
